Vulnerabilities in USB drivers for Windows could allow an attacker to take control of locked workstations using a specially programmed Universal Serial Bus device, according to an executive from SPI Dynamics, which discovered the security hole. However, SPI tested attacks on Windows systems, but any operating system that is USB-compliant is probably vulnerable.

Ok, I'm going to be harsh here:
Great, you post anonymously on a security related thread, throw a name around and expect us to believe you?
At least PGP signing your post with a verifiable key might be a begining of trust.
Don't take it personnaly, I'm no authority when it comes to security or kernel topics, but it seems obvious to me that you have to back up your claims somehow.

Well ok I was really harsh, and after reading your post again, you don't make it so authoritative as I'm implying in my previous post. Still, your name doesn't bring anything to your arguing without being certified somehow.

You are right for the most part. The technology, multi-user kernel extensions, was integrated into the kernel for Windows 2000 Server. I'm not sure exactly what changes (if any) were made to the multi-user model but there were overhead reductions. I've found almost no info on the extensions online. SFU on Windows uses the UNIX model.